The use of substantially cylindrical rotating scrub brushes in automatic and semiautomatic car washing systems is now a wide-spread, if not universal, practice. Vertical side brushes may be mounted on laterally pivotal arrangements for contacting the side surfaces of a vehicle as it travels along a wash lane. Horizontal top brushes may also be suspended from various types of overhead support arrangements to wash the top surfaces of a vehicle as well as the front and rear windows and portions of the front and rear end surfaces of the vehicle. It is well known that the location and configuration of vehicle body and trim members often makes the thorough scrubbing of a vehicle very difficult where only rotating brushes are used since there is little, if any, relative displacement between the vehicle and the brush along the axis of rotation of the brush. Since thoroughness is a virtue in a car washing operation, it is typical to augment the brush wash with hand washing or detergent gun washing, such operations necessarily adding to the cost of operating a car wash business. Accordingly, it is desirable to have an entirely mechanized system which will perform a complete and thorough washing job.